1. Field of the Invention
This invention relates generally signal balancing, specifically to a method, system and software for balancing signals spanning multiple voltage domains.
2. Background of the Invention
The semiconductor industry is constantly increasing the number of circuits and functionality that can be compressed onto a single die. As process dimensions decrease, this ability has grown at an astronomical rate. The ability to put entire functioning systems on a single die is now the norm rather than the exception. As a consequence of this growth, the die/integrated circuit can be viewed as compilation of functioning islands.
Some of these islands operate at different voltages from one another, others have the ability to switch to standby or sleep mode, while still others result from the need to isolate noisy circuitry. The ability to combine these different islands onto a single integrated circuit, requires techniques and circuitry for propagating communication (clocks, signals, etc), power, and output results.
In a design without Voltage Islands, the entire signal operates on identical power rails. Even though the voltage varies between best case (“BC”) and worst case (“WC”) conditions, every buffer on the power rail is assumed to operate at an identical voltage for balancing purposes. However, with the use of Voltage Islands signal buffers are powered by separate power rails. As a result the signal's buffers operate at various voltage conditions between voltage islands and voltage domains to be balanced.